Video tape record cassettes are commonly distributed on a rental basis. It is therefore important to be able to determine the number of times a taped program is displayed, both for calculating the rental fee and for retiring the tape in due season.
Attempts have previously been made to determine playing time of video cassettes. U.S. Pat. No. 3,604,624 connects the incremental indicator to the drive shaft of the recorder for indicating the time of playing during a single showing. A pivoted pointer mounted between the reels and contacting the tape on one reel is used in U.S. Pat. No. 3,630,170 to measure the time of play. U.S. Pat. No. 3,678,215 counts the number of times the cassette is inserted into and removed from the recorder.
A different approach is used in U.S. Pat. No. 3,995,319 wherein is recorded the number of times the tape is transferred between a first and a second reel, using a pivoted sensing arm which, however, is capable of independent pendulum-like movement upon impact.